Douglas McMaster is, in his own words, “ferociously passionate” about stamping out food waste. The chef grew up in a small northern mining town called Retford, climbing the ranks to pioneer a new era of turning leftover ingredient parts into high-end gastronomy.

While living in Australia, he met waste artist and eco-designer Joost Bakker, who helped define McMaster’s food philosophy. With Bakker, he created the world’s first zero-waste café in Melbourne in 2011.

Following his stint Down Under, he returned to Britain and upped the stakes, opening Silo in Brighton in 2014. More recently, he collaborated with drinks maestro Ryan Chetiyawardana to work on Cub, where diners enjoy a pairing menu of zero-waste, plant-based food and cocktails.

We asked McMaster his recipe for ridding restaurants of waste.

I grew up in a tough little miner’s town. Where I’m from, food was fuel, that was it. A hotel restaurant serving microwave food was my first job, but I just loved being in a kitchen. So I thought, ‘If I’m going to do this, I’m going to be the best.’

Winteringham Fields was my first proper job in the north. When I was there, it had two Michelin stars. It was the stereotypical 18-hour day. You live it. There is no life outside those kitchens. Live it, love it or get out.

James Lowe at Lyle’s was a major influence for me. He was my head chef at St. John when I moved to London at 20. He has the DNA of St. John, but it was his own particular attitude to food which became the biggest influence on my cooking. His mentorship and direction. He wrote that [BBC Young Chef Award] menu with me.

Joost Bakker is my sustainability inspiration. He’s not a chef, he’s a designer and an artist that’s done loads of installations for different restaurants. His inspiration is turning waste materials into artwork. He’s a Dutch guy with a big passion for natural food and natural farming – but not gastronomy.

Before I opened Silo, I had an epiphany. I researched food history, particularly how food was used during the war, and learnt that back then we put food into the hands of big business and factories. So I am going back to how food was before processed food became popular. The war forced us to develop unnatural food. Silo is a response to that – it is simply natural food.

The natural food system is by default sustainable. Zero waste is the catch, the hook. In nature, there is no waste. Waste is something we’ve created as humans. What Silo is doing is looking at the natural food system hundreds of years ago, before food was industrialised.

Who isn’t talking about sustainability and waste? You can’t get away from it. But four years ago, no one was talking about it. I thought, 'Is this too much, does anyone care?' Then, boom, it exploded. I credit Silo’s success to the relativity of the idea. Silo is a success because of it. The sustainable food movement isn’t only happening because of Silo, of course. It was just incredible timing.

The sustainable food movement will trickle down to high-street restaurants. One easy change restaurants can make is to think more about direct trade. If you’re in a country or village pub, think, ‘Right, what farms are around me?’ Instead of getting veg from a wholesaler, get veg from a farm. It’s so much more liberating trading with direct sources.

Cooking with less meat is a key way to be more sustainable. The production of meat creates waste in itself – just to get the meat to the plate requires energy and waste.

image credit: Xavier D. Buendia

There’s no such thing as a by-product. Look through our Silo Instagram… everything has its purpose. At Silo, there’s so many bits of food you’d never consider using that are championed to the point of being precious. And composting. Turn all of your food waste into compost.

Potato skin miso, for instance, is such a treasure. Potato skins fermented and roasted for two weeks, it’s an amazing product. We don’t allow it to go in the bin.

In terms of sustainable ingredients, why not try seaweed? We’re on an island and there’s a lot of seaweed around us, more than we could possibly desire.

I have a list of off-grid ingredients. They’re not necessarily wild, but just abundant and off our radar. Whey [a cheese by-product] is an ingredient that’s getting popular with chefs but not the public. If you think how much cheese is in the world, then you times that by four, there’s that much whey in the world. When you make cheese, you turn milk, and what happens to all that whey? I’ve witnessed it getting thrown away in its absolute monstrous mass. Through massive silos and vats. Filtered into a drain. At Cub, it’s one of our favourite ingredients. It’s been described as like crack, we love it so much.

Here’s how we use the whey that’s normally thrown out. We reduce it by fifteen times, so it’s really caramelised. Its natural high-protein value makes it really ‘caramel-y’ when you reduce it. But it has a savouriness to it and a sour presence, depending on which dairy you get it from. We get ours from Neal’s Yard, and it’s very acidic, very rich, very sour and very sweet.

Weeds, nettles, hogweeds and alexanders are the other trending foods on my mind right now. They have softer flavour palettes – they’re subtle, but you can introduce huge flavours to them too.

How is it possible to work in such a small kitchen and not compromise on quality? We take away meat and fish. They both require space so immediately they were taken out of the design.

We also prepare food simply, there’s no elaborate plating. One single plate will do every dish. We designed a menu based on incredibly limited space. It’s a huge process of elimination to design the menu, all the while not compromising on quality.

image credit: Xavier D. Buendia

I don’t like expensive food. I don’t go to expensive restaurants. I hate going to restaurants and spending 150 quid and knowing I’m paying for their chandelier and expensive, embroidered cushions. I don’t want to pay for that – that’s their fetish. I like true cost. You’re paying for a product. Maybe it’s because I’m from a small northern miner’s town; I want to be accessible for everyone.

People say it costs loads of money to buy a flour mill and a compost machine, but you don’t have to have those. There’s loads of ways of being sustainable which cost nothing.

Our food waste goes to a guy called Igor. He takes waste from all the Michelin-star restaurants down to his plot, then ferments it and turns it into compost, and uses that to grow food, and that food goes back into restaurants. You pay him £7 a wheelie bin, and for that £7 you get produce the equivalent of £7, grown from food waste. It’s a perfect closed loop: direct, no waste.

In the food world, there’s a stigma attached to cocktails. People think they don’t work with food. But a cocktail can be anything, just a bit of liquid in a glass. Here, we say they definitely work with food. Lower ABV cocktails – which are not as strong and are therefore cheaper – is how we’re proving that, economically, cocktails can work as well as wine. Plus, you can tailor the flavour of a cocktail so much further than wine. Having the ability to tailor a dish to a drink is amazing.

Zero waste is an extreme, idealistic idea. But by using extreme examples, you make a statement. We’re putting our flag in the sand, at its most controversial position, and that’s what makes people react, provokes people, and at the very least, makes them think.

Never put your ideas before your customers’ satisfaction. It happens so often on the Millennial food scene. The vector is pointed at the chef, ‘look at what I’m doing,’ but it’s about the guest’s experience. Eating out a lot is essential to understand how the guests see the experience.

Silo is provocative – for my sins and to my detriment. Sometimes I look back at times in Silo’s history and think, I pushed it too far then, by having dishes that were a little bit too abstract. Serving raw jellyfish, which tastes alright, for example. At times I’ve been a bit too gung-ho with ingredients. You live and you learn.